JP2011070869A - Ceramic metal halide lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable to light with arc stabilized from initial lighting, even if cerium iodide as halogenated metal is added to an arc tube. <P>SOLUTION: In the ceramic metal halide lamp (L) in which an arc tube (1) formed of a light-emitting part (2) and capillaries (3A, 3B) being inserted with a pair of electrode assemblies (6A, 6B) at either end of the arc tube parts of translucent ceramics is housed in a translucent outer tube (10) and cerium iodide as halogenated metal is added, a closed-loop type arc tube support frame (F) equipped with two parallel props (12R, 12L) extended along a length direction from a base-end (10a) side with a base (11) formed to a tip (10b) side is welded and fixed to a stem lead (18b) receiving power supplied through the base (11), inside the outer tube (10), and at the same time, a power-feeding wire (8) is connected to the base-end side for feeding electricity to a tip-side electrode (5B) of the arc tube (1). <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a ceramic metal halide lamp to which cerium iodide is added as a metal halide.

The metal halide lamp emits light that is closest to natural light compared to a high-pressure sodium lamp or a mercury lamp, and therefore has excellent color rendering properties, and is also used as a base lighting in offices and stores.
In general, an average color rendering index Ra = 80 or higher, which is ISO 8995 color rendering category 1B or higher, and a high color rendering in which the correlated color temperature is in the range of 3000 to 4500K, and a light source in a range from warm to white is used. From the viewpoint of energy saving, a lamp with higher luminous efficiency is demanded.
However, high color rendering and high efficiency are contradictory effects. If the color rendering is improved, the luminous efficiency is lowered, and if the luminous efficiency is increased, the color rendering is lowered.
For this reason, the conventional metal halide lamps are classified into either an efficiency-oriented type or a color rendering property-oriented type even if high efficiency and high color rendering are desired.
In this case, generally, if the average color rendering index Ra ≧ 80, it is evaluated as high color rendering (ISO 8995 color rendering category 1B or higher), and if the luminous efficiency η ≧ 100, it is evaluated as high efficiency.

  For example, the highest data of the Dy-Ho-Tm metal halide lamp disclosed in Patent Document 1 is excellent with an average color rendering index Ra = 87, but is slightly inferior with luminous efficiency η = 93 (lm / W). It can be said that it is an important type.

  The Na—Ce-based metal halide lamp disclosed in Patent Document 2 is excellent with an average luminous efficiency η = 123 (lm / W) due to intense green light emission of Ce, but is slightly inferior with an average color rendering index Ra = 60. It can be said that it is an efficiency-oriented type (see Patent Document 2 [0049]).

  Further, Patent Document 2 [0082] states that “in addition to NaI, dysprosium (Dy), thulium (Tm), holmium (Ho), thallium (Tl), etc. are appropriately used depending on the desired lamp characteristics. However, even if these substances are added to adjust the ratio of the luminescent encapsulating substance of the Na—Ce metal halide lamp, the intense green light emission of Ce is suppressed and Ra = Not only is it difficult to make it 70 or more, but when Dy, Tm, Ho, and Tl are added as light emitting substances, the lamp characteristics of Patent Document 1 are approached and the light emission efficiency is lowered.

  On the other hand, conventional high color rendering ceramic metal halide lamps achieve high color rendering and high luminous efficiency by increasing the heat insulation effect of the arc tube by evacuating the translucent outer tube that houses the arc tube. Since the arc tube is difficult to be cooled when the lamp is turned off, it takes about 25 to 30 minutes to restart the lamp after it is turned off, and it is desired to reduce this to about 15 minutes.

Although it is possible to shorten the restart time by increasing the starting pulse voltage, when a pulse voltage that can be restarted within 15 minutes was measured in a prototype lamp with a vacuum inside the translucent outer tube, a high voltage pulse of 3 kV or higher I found that it was necessary.
In the recent usage environment that emphasizes safety and security, it is considered that a starting voltage of about 1 to 1.5 kV is appropriate. In a general lighting lamp of a low starting voltage type that is lit by a mercury lamp ballast, it is desirable to avoid generating a high voltage pulse of 3 kV in terms of safety.

  Therefore, the present inventor has achieved both high color rendering and high efficiency, which are contradictory effects in a metal halide lamp, and specifically, the luminous efficiency η ≧ while maintaining the high color rendering of an average color rendering index Ra ≧ 80. A lamp has been developed that achieves a high efficiency of 100 (lm / W) and shortens the restart time with a starting pulse voltage comparable to that of a conventional lamp (see Japanese Patent Application No. 2009-148358).

As shown in FIG. 3, the lamp 20 has a light emitting part 2 in which a metal halide, mercury and a starting rare gas are sealed, and capillaries 3A and 3B arranged at both ends thereof, which are formed of a translucent ceramic. The tube 1 is accommodated in the translucent outer tube 10.
A pair of electrode assemblies 6A and 6B including electrodes 5A and 5B are inserted into capillaries 3A and 3B formed at both ends of the light emitting unit 2, and are hermetically sealed.
In the outer tube 10, two parallel struts 12 </ b> R and 12 </ b> L extending along the longitudinal direction from the proximal end 10 a side of the outer tube 10 in which the base 11 is formed to both ends of the arc tube 1 to the distal end 10 b side. A closed loop type power feeding and combined arc tube support frame 21 in which a positioning fitting 13 is welded is disposed at the tip of the tube.

The support frame 21 is a ring that prevents the displacement of the support frame 21 by being abutted on the inner surface of the outer tube tip 10b on the tip side of the two parallel columns 12R and 12L formed by bending both ends toward the outer tube tip side. 3 is welded to form a square closed loop when viewed from the direction of FIG. 3, and the arc tube 1 is supported via a pair of support disks 16A and 16B.
Since the support frame 21 is formed in a closed loop type, it has high rigidity and is difficult to be deformed even when an external force is applied. When the support frame 21 vibrates due to an external force acting on the lamp 20 during transportation, the support frame 21 is deformed. As a result, the arc tube 1 is not displaced, and the weakly formed capillaries 3A and 3B formed at both ends thereof are not damaged.
In particular, in a lamp with a built-in starter, circuit components are attached to the support frame 21. Therefore, if the support frame 21 has high rigidity, the start circuit is less likely to be destroyed due to the influence of vibration or the like.

  The stem 14 formed inside the base 11 is provided with a pair of stem leads 18A and 18B that receive power supply via the base 14, and one electrode protruding from the capillary 3A of the arc tube 1 is provided. The lead 7A is connected to one stem lead 18A, and the other electrode lead 7B is supplied with power through a metal lead 22 attached to the distal end side of the support frame 21 welded to the other stem lead 18B. ing.

  That is, the support frame 21 that is a conductor extends from the base end 10a side of the outer tube 10 on which the base 10 is formed to the tip 10b side where the electrode lead 7B of the arc tube 1 is disposed. It was conventional technical common sense to use as a member.

The arc tube contains at least thulium iodide, thallium iodide, sodium iodide and calcium iodide as the metal halide, and sodium iodide and calcium iodide are contained in the total metal halide. Each is encapsulated in a molar ratio of 40-80% and less than 30%.
If necessary, for example, when improving the luminous efficiency, cerium iodide is enclosed in a molar ratio of 5% or less with respect to the total metal halide.

  When cerium iodide is added to this lamp 20, if it is lit stably, it becomes a lamp with excellent color rendering properties and luminous efficiency. However, when it is lit vertically, the arc is stabilized for several tens of hours at the beginning of lighting. In other words, it has been found that the arc may be bent, the arc voltage may be changed, or the lamp voltage may be greatly changed to change the emission color or cause the lamp to disappear. This is a unique phenomenon seen with lamps containing cerium.

That is, since power is supplied to the electrode 5B on the distal end side of the arc tube 1 via the metal lead 22 connected to the distal end side of the closed loop type support frame 21, two wires are provided from the stem lead 18B standing on the stem 14. Two power supply routes reaching the metal lead 22 through the parallel columns 12R and 12L are formed.
Therefore, to start the power supply, for example, as shown in FIG. 4, the parallel struts 12R, a current flows in the arrow _{A 1} direction 12L, the magnetic field _B 1, _{B 2} are formed, the magnetic field _B 1, _{B 2} The light emitting part 2 is located inside.

Since the electrode 5A, the arc between 5B current flows in the arrow _{A 2} direction, relative to an arc, each of the parallel struts 12R by Fleming's left hand rule, force _W 1 in a direction away from the 12L, _{W 2} acts.
That is, at this time, since the two magnetic fields B ₁ and B _{2 in the} opposite directions are acting at the intermediate portions of the parallel struts 12R and 12L, the two forces W ₁ and W _{2 in the} opposite directions are also applied to the arc. Act simultaneously.
Then, the polarity is inverted by an alternating current, the parallel struts 12R, current flows in opposite to the arrow _{A 1} direction 12L, electrodes 5A, even when the current flows in opposite to the arrow _{A 2} direction between 5B, parallel struts 12R, the 12L A similar phenomenon occurs because two magnetic fields in exactly opposite directions are generated in the middle part, and a force acts on the arc in a direction away from the respective parallel struts 12R and 12L.
Therefore, since the arc is pushed from both sides, there is no place to go in the direction of the force (left-right direction as viewed in FIG. 4), and the direction perpendicular to this (the direction toward the front or back of the page as viewed in FIG. 4). ) Turns into an unstable state.
Moreover, in the case of containing cerium, the arc discharge route is not stable because the excess additive present in the arc tube does not evaporate evenly at the beginning of lighting. Thus, it is considered that the arc oscillates by repeating the arcs coming and going due to the delicate balance of the force.

JP 2003-187744 A JP 2003-086130 A

  Therefore, the present invention has a technical problem to make it possible to stabilize the arc from the beginning of lighting even when cerium iodide is added to the arc tube when a closed-loop support frame is formed.

  In order to solve this problem, the present invention is a translucent ceramic comprising a light emitting part enclosing a metal halide, mercury and a starting rare gas, and capillaries through which a pair of electrode assemblies arranged at both ends thereof are inserted. In the ceramic metal halide lamp in which the formed arc tube is housed in the translucent outer tube and at least cerium iodide is added as the metal halide, the arc tube is formed from the base end side where the cap of the outer tube is formed. A closed-loop arc tube support frame with two parallel struts extending along the longitudinal direction through both sides of the tube to the tip side is welded and fixed to the stem lead that receives power supply through the base, and is arranged in the outer tube. At the same time, a single feed wire for energizing the tip side electrode of the arc tube is connected to the base end side.

According to the ceramic metal halide lamp according to the present invention, when a closed-loop type support frame that supports the arc tube is disposed, the single electrode that feeds power to the tip side electrode of the arc tube without passing through the support frame. A feeding wire was provided.
Since the support frame is formed in a closed loop type, it is difficult to deform even when an external force is applied. When supporting a weakly formed capillary formed at both ends of the arc tube, the external force acts on the lamp during transportation. The arc tube will not be displaced or damaged due to deformation of the frame when it vibrates.
Further, in the starter built-in type lamp, the starter circuit component attached to the closed loop type support frame is not destroyed by the deformation of the frame.

Then, power is supplied to the tip side electrode of the arc tube by providing a separate power supply wire without going through the support frame.
As a result, no current flows through the two parallel struts located on both sides of the arc tube, so that a magnetic field in the opposite direction is not formed between the parallel struts.
Although a magnetic field is formed around the power supply wire, only a unidirectional magnetic field is formed in a portion where the arc is formed. Therefore, even if the magnetic field is affected, the arc is rarely unstable.

Explanatory drawing which shows an example of the ceramic metal halide lamp which concerns on this invention. The figure which shows the force which acts on an arc at the time of the electricity supply. Explanatory drawing which shows the conventional ceramic metal halide lamp. The figure which shows the force which acts on an arc at the time of the electricity supply.

  Even if cerium iodide is added to the arc tube, in order to achieve the purpose of stabilizing the arc from the beginning of lighting, a light emitting portion in which metal halide, mercury and a starting rare gas are sealed, and both ends thereof A ceramic metal halide lamp in which a light-emitting tube formed of a translucent ceramic with a capillary inserted through a pair of electrode assemblies is housed in a translucent outer tube and cerium iodide is added as the metal halide A closed-loop arc tube support frame having two parallel struts extending along the longitudinal direction from the base end side of the outer tube on which the base is formed to both sides of the arc tube to the distal end side is provided via the base. A power supply wire is welded and fixed to the stem lead and is arranged in the outer tube. Connection was.

A ceramic metal halide lamp L shown in FIG. 1 includes a luminous tube 1 and a non-linear ceramic capacitor for supplying a starting voltage between its electrodes 5A and 5B in a translucent outer tube 10 having a base 11 formed at one end. A vessel 9 is arranged.
The arc tube 1 has a transition curved surface in which a pair of capillaries 3A and 3B have no corners at both ends in the major axis direction of the light emitting unit 2 formed in a substantially elliptical shape that is rotated about the major axis of the ellipse. 4, the light emitting section 2 is filled with a metal halide, mercury, and a starting rare gas.

The arc tube 1 of this example uses a so-called one-piece type in which the light emitting part 2 and the capillaries 3A and 3B are integrally molded by molding a powdered compact of translucent alumina.
A pair of electrode assemblies 6A and 6B having electrodes 5A and 5B are inserted into the capillaries 3A and 3B formed at both ends of the light emitting unit 2, and both ends of the capillaries 3A and 3B are electrically insulated frit. At the same time as being hermetically sealed by a sealing material such as glass, the electrode assemblies 6A and 6B are fixed at fixed positions in the capillaries 3A and 3B by the sealing material.

Note that the light emitting portion 2, a metal halide, at least iodide thulium _(TmI 3), thallium iodide (TlI), along with sodium iodide (NaI) and calcium iodide (CaI ₂₎ is enclosed, iodine Sodium iodide (NaI) and calcium iodide (CaI ₂ ) are encapsulated in molar ratios of 40-80% and less than 30%, respectively, with respect to the total metal halide.
Further, cerium iodide (CeI ₃ ) is enclosed in a molar ratio of 5% or less with respect to the total metal halide.

Further, in the outer tube 10, a closed-loop type light emission provided with two parallel columns 12 R and 12 L extending along the longitudinal direction from the base end 10 a side to the tip end 10 b side of the outer tube 10 in which the base 11 is formed. A tube support frame F is arranged.
The support frame F is formed with two parallel struts 12R and 12L having the same length by bending both ends of the metal linear member 12 toward the distal end 10b of the outer tube 10, and the distal end of the outer tube is formed at the distal end. A ring-shaped positioning fitting 13 that is brought into contact with the inner surface of 10b and prevents the frame tip from being displaced is welded to form a square closed loop as seen in FIG.

  A pair of support disks 16A and 16B are attached to the two parallel struts 12R and 12L, and the capillaries 3A and 3B are inserted into insertion holes (not shown) formed at the centers thereof, so that the arc tube 1 is installed. The translucent sleeve 17 is fixed to the discs 16A and 16B so as to surround the light emitting portion 2 while being attached and supported.

On the other hand, the stem 14 formed inside the base 11 is provided with a pair of stem leads 18 </ b> A and 18 </ b> B that receive power supply via the base 11.
A power supply lead 7A protruding from the end of the proximal capillary 3A is connected to one stem lead 18A.
Further, the support frame F is fixedly welded to the other stem lead 18B on the base end side, and the power supply lead 7B protruding from the end of the distal end side capillary 3B is connected to the base end of the frame F via one power supply wire 8. Connected to the side.
In this case, the feed wire 8 is preferably connected to a base portion 12C formed between the parallel struts 12R and 12L of the support frame F.
The power supply lead 7B on the distal end side is insulated and supported on the distal end side of the frame F via the insulator 19, and protects the capillary 3B that is easily broken by vibration or the like.
Further, the starter 9 is electrically connected between the power supply leads 7A and 7B.

The above is one configuration example of the present invention, and the operation thereof will be described next.
When the base 11 of the ceramic metal halide lamp L is mounted on a lamp socket (not shown) and a switch (not shown) is turned on, a lamp current flows between the electrodes 5A and 5B and the lamp is turned on.
At this time, since the provided in the base portion 12C of the welding point P ₂ are both frame F of the welding point P ₁ and the feed wire 8 of the stem lead 18A of the support frame F, is supplied from the stem leads 18 current welding point _{P 1} - most flows in the parallel strut 12R- alignment ferrule 13 parallel struts 12L- root welding point _{P 2} - base 12C- flow through the root of the weld point _{P 2,} the weld point _{P 1} Even if it flows, the influence of the magnetic field is negligible.

Therefore, as shown in FIG. 2, there is only one feeding wire 8 as an element for forming a magnetic field between the electrodes 5A and 5B where the arc is formed, and the feeding wire 8 has, for example, an arrow A _1. When a lamp current is supplied in the direction, a magnetic field B is formed around the feed wire 8.
Electrodes 5A, since it is formed arc is between 5B, will flow a current in the opposite arrow A ₂ direction to the current flowing through the power supply wire 8 in a magnetic field B, and the arc, Fleming left hand A force W in a direction away from the wire 8 works according to the law.

Further, when the lamp current to the power supply wire 8, for example, in opposite to the arrow A ₁ direction is supplied, although the magnetic field B around the feed wire 8 magnetic field opposite is formed, the electrodes 5A, the arc between 5B Once generated, the electrodes 5A, the inter-5B will flow a current in opposite to the arrow a ₂ direction opposite to the current flowing through the power supply wire 8, with respect to an arc, away from the wire 8 by Fleming's left-hand rule Directional force W works.

  That is, no matter which direction the lamp current flows, only the force W in the same direction away from the feeding wire 8 acts on the arc, and the force in the opposite direction (direction approaching the feeding wire 8) acts simultaneously. Therefore, the arc does not act in an alternating manner by an alternating lamp current and is not pulled sequentially in a plurality of directions.

  As described above, the present invention can be applied to ceramic metal halide lamps used as base lighting for offices and stores.

L ... Ceramic metal halide lamp 1 ... Arc tube
2 ... Light emitting part
3A, 3B ......... Capillary 5A, 5B ......... Electrodes
6A, 6B ......... Electrode assembly 8 ......... Feeding wire 10 ......... Outer tube 11 ......... Base 10a ......... Base end 10b ......... Tip 12R, 12L ......... Parallel post F ......... Support frame

Claims (3)

An arc tube formed of a translucent ceramic with a light emitting part enclosing a metal halide, mercury, and a rare gas for starting, and a capillary inserted through a pair of electrode assemblies arranged at both ends of the light emitting part is provided in the translucent outer tube. In a ceramic metal halide lamp that is housed and to which at least cerium iodide is added as the metal halide,
A closed-loop arc tube support frame having two parallel struts extending along the longitudinal direction from the base end side where the cap of the outer tube is formed to both sides of the arc tube to the distal end side is provided via the cap. A ceramic metal halide which is fixedly welded to a stem lead which receives power supply and is arranged in an outer tube, and a power supply wire for energizing a distal electrode of the arc tube is connected to the proximal end side thereof. lamp.   A pair of support disks are attached to the support frame at a predetermined interval, and the arc tube is supported by inserting a capillary of the arc tube through an insertion hole formed in the center of the support disk, and from the distal end side capillary. 2. The ceramic metal halide lamp according to claim 1, wherein the protruding power supply lead is supported by a support frame via an insulator. 3. The ceramic metal halide lamp according to claim 2, wherein the arc tube has the capillary continuously formed through transition curved surfaces having no corners at both ends in the major axis direction of the light emitting portion formed in a substantially elliptical shape. .

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